In the past, aneurysms have been addressed by various treatment techniques such as the surgical resection of the aneurysm and the implantation of an artificial blood vessel (a tube made of an artificial material) at the resectioned region. As an alternative, so-called bypass surgery has been used in which another new blood vessel path is formed to secure blood in the past. However, generally speaking, patients who develop an aneurysm are generally aged or older persons. Undergoing a major surgery places a heavy burden on patients and can create difficulties in many cases. In addition, complications during or after the surgery are possible and carry risks.
Recently, another treatment technique (aneurysm embolization) has been developed in which an embolic material is percutaneously supplied to and filled in the aneurysm of a blood vessel from a femoral region or the like. This treatment technique provides an advantage of significantly reducing the risk of surgery and burden on the patient. Such a treatment technique uses an elongate medical body in which a coil-like embolic material (embolic coil) connected to the tip of the main body of an elongate body (see e.g., Japanese Patent Laid-open No. Hei 7-265431, hereinafter referred to as Patent Document 1).
When the elongate medical body in Patent Document 1 is used, it is percutaneously introduced into a blood vessel. Then, the tip of the elongate body is advanced to a target region or the position of the aneurysm of the blood vessel in the brain under X-ray illumination. High-frequency current is supplied to the aneurysm via the main body of the elongate body to thermally resect a joint between the main body of the elongate body and the embolic coil. Thus, the embolic coil is supplied to and filled in the aneurysm.
With the medical elongate body of Patent Document 1, however, if the joint between the main body of the elongate body and the embolic coil is resected and the embolic coil is once implanted, it is impossible to remove or recover the embolic coil. Because of this, if the embolic coil is not implanted at the desired position, it is necessary to recover the embolic coil by other ways and implant a new embolic coli, thus burdening the patient.
Additionally, when the joint between the main body of the elongate body and the embolic coil is resected, dissolved material or the like may flow into the living body from the joint, even though in minute amounts. From a safety standpoint, it is preferable to eliminate the outflow of such a material.